<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>两栏等高布局</title>
  <style>
    .box{
      border-left: 200px solid black;
      background: #f5f5f5;
      color: #fff;
      clear:both;
    }
    .right{
      color: #000;
    }
    .left{
      float: left;
      width: 200px;
      margin-left: -200px;
    }
  </style>
</head>
<body>
  <div class="box">
    <div class="left">
      <ul>
        <li>1</li>
        <li>12414</li>
        <li>12414</li>
        <li>12414</li>
        <li>12414</li>
        <li>12414</li>
        <li>12414</li>
        <li>12414</li>
      </ul>
    </div>
    <div class="right">
      <article>问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a问猴子那个a</article>
    </div>
  </div>
</body>
</html>